1. Field of the Invention
The present invention relates to a traveling and accelerating system for bicycles, and more particularly to, an improved traveling and accelerating system for bicycles by which the bicycle may travel forward regardless of rotation direction of pedals and accelerated travel is also possible without changing gears.
2. Description of the Prior Art
In general, bicycles include front and rear wheels, pedals to generate power by being stepped by a user, and a power transmission means to transfer the power generated by rotation of the pedals to the rear wheel.
The power transmission means includes a driving sprocket mounted at the pedals, a driven sprocket having a latch for transmitting power toward the rear wheel in one direction, and a chain to connect the driving sprocket to the driven sprocket.
The driven sprocket is provided with a latch member to be engaged with the rear wheel only in one direction.
As described above, the conventional bicycle travels only in one direction, that is, in the forward direction by rotation power which is generated by rotating the pedals forward and transmitted through the chain connecting the driving sprocket to the driven sprocket.
Therefore, the user has to rotate the pedals only in the forward direction, and such a same movement makes the user""s leg-muscles unbalanced and makes the user feel bored and tired easily, while it is impossible to relieve his fatigue while riding the bicycle.
In the conventional traveling device, even though it is possible to stop rotation of the pedals or rotate the driving sprocket and the chain reversely in response to reverse rotation of the pedals, the power is cut off and not transmitted by a forward latch means provided inside the driven sprocket so that the driven sprocket races.
In order to resolve the above disadvantages, Korean Patent Publication No. 95-13589 has suggested a reverse traveling device which includes a forward clutch to alternatively transmit driving power to a driving sprocket, a feed shaft of which engagement state is changeable by means of an operation lever, an idle gear and a reversing gear wheel, so that the bicycle may travel forward even in case of backward rotation of the pedals, developing the user""s feet and legs in balance.
The reverse traveling device has, however, still problems that the structure thereof is too complicated and this reverse traveling device cannot be adapted to the driving wheel at the driven sprocket side of the currently widespread bicycles, so that a new bicycle should be purchased.
Furthermore, such a proposed reverse traveling device has no change gear, so that there is a tendency to avoid use of it.
Accordingly, it is an object of the present invention to provide a traveling and accelerating system for bicycles which may transmit power in case of not only forward rotation but also backward rotation of pedals.
It is another object of the present invention to provide a traveling and accelerating system for bicycles which may operate in both forward and backward directions of pedal rotation so that users may develop their leg-muscles in balance without feeling as bored and tired as riding the prior art bicycle.
It is a further object of the present invention to provide a traveling and accelerating system for bicycles which is provided with a change gear integrally for accelerated traveling so that an additional change gear is not necessary any more and users may purchase a bicycle at a relatively low cost.
To achieve the above objects, the present invention is directed to a traveling and accelerating system for bicycles which includes a frame having a front wheel at a front part and a rear wheel at a rear part thereof; a pair of pedals fixed at both sides of a shaft which is rotatably supported at a boss being fixed under a center of the frame, to be driven by a user""s feet; a driving sprocket axially fixed on the shaft for transmitting rotation power via a chain to the rear wheel; a housing attached at one side of the boss to be closed with a cap and having a hollow cross-sectional shape to accommodate accessories; a pinion axially fixed on the shaft beside the driving sprocket in the housing; a first gear member accommodated in the housing and having an inner gear part along its inner diameter; a second gear member movably contacting the first gear member and provided with planetary gears to be engaged with the inner gear part of the first gear, the planetary gears being fixed by pins and rotatable in relation to the pins; a pair of latch means respectively inserted and fixed in the first gear member and the second gear member by being penetrated with a shaft of the pedals so as to rotate the gear members respectively in one direction; and a conversion control part connected to a release cable outside the housing for setting a travel mode or an acceleration mode corresponding to rotation directions of the pedals by controlling engagement of the first gear member and the second gear member according to the user""s selection.
According to the traveling and accelerating system for bicycles of the present invention, the user may simply change the pedals"" rotation direction forward and backward by operating the conversion lever while keeping forward traveling of the bicycle, thereby promoting balanced development of leg-muscles.
Also, it becomes possible to selectively accelerate traveling speed by increasing rotation number with relation to a certain rotation.